Adjustable bracket.



E. B. CRAFT.

ADJUSTABLE BRACKET.

AIfPLIOATION nun MAB.25,190,5.

Patented May 11, 1909. L

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EDWARD B. CRAFT, OF CHICAGO, ILLINOIS, ASSIGNOR 'IO WESTERN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ADJUSTABLE BRACICET.

Application filed March 25, 1905. Serial No. 252,054..

Specification of Letters Patent.

Patented May 11, 1909.

To all whom it may concern:

Be it known that I, EDWARD B. CRAFT, citizen of the United States, residing at Chicage, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Adjustable Brackets, of which the following is a full, clear, concise, and exact description.

My invention relates to an adjustable supporting bracket, and has for its object to provide an improved and simplified structure which will furnish a stable support for a telephone or other device with which it may be associated.

My invention contemplates in general a bracket comprising one or more pairs of opposed toggle levers connected together and provided with suitable supports having means for constraining the ends of the levers to move along definite lines, so that force applied to the bracket other than in the direction of its expansion and *contraction, will have no effect upon the adjustment thereof. This feature is of great advantage, as for example, where the bracket is used to support a telephone set. When so utilized, the direction of collapse and expansion is usually horizontal, and the weight of the telephone set, together with the force exerted in placing the telephone receiver upon its hook will apply considerable force to the bracket in a vertical direction. With my arrangement, this force could have no effect upon the bracket, which is looked, as to force applied thereto other than in a horizontal plane. Thus the bracket may be adjusted to any desired position and is at all times stable in any of its positions of adjustment.

In the preferred form of my invention, I employ a pair of opposed toggle levers pivotally connected with each other at their ends, and provided with supporting plates having main slots in which the pivots uniting said levers are adapted to reciprocate. Each plate is provided with two slots, angularly disposed with relation to the main slot therein and on either side thereof, each toggle lever having a pin at each end adapted to ride in one of said angular slots, to apply a constraining force to the levers and maintain the bracket stable in any adjusted position. Each link of the toggle levers is thus given a train movement and the bracket may be lengthened and colla sed as desired; but when force is applied tiereto in any direction other than in the direction of its expansion or contraction, the four pins in their respective slots form a lock or balanced parallelogram of forces which renders such applied force ineffective.

I will describe my invention more particu larly by reference to the accompanying drawing which illustrates in elevation a bracket embodying my invention, showing it employed to support a telephone set and in its collapsed or contracted position, the open or expanded position of the bracket being shown in dotted lines.

The supporting bracket illustrated in the drawing, comprises a pair of opposed toggle levers a l) pivotally united with each other at their ends a b and a. b and mounted in supports 0 (Z, respectively, in such manner as to have compound tram movements, so that force applied to the bracket other than in the direction of its collapse or expansion, will be without effect thereon. The pivots uniting the ends a b and a t of said lovers are mounted to reciprocate in horizontal slots 0 (1, respectively, in said supporting plates 0 (Z. Each supporting plate is provided with two slots it h disposed angularly with relation to the horizontal or main slot therein,

preferably at right angles to said slot and on each side thereof, and each toggle lever is provided at its opposite ends with pins 6 (2 adapted to ride in the slots in the supporting plates 0 d, respectively. With this arrangement of reciprocating pivots and guides or pins, the links of each toggle are given tram movements and the connected ends of the links of opposed toggles provided with compound tram movements. It will thus be seen that by applying force to the bracket in a horizontal plane, the same may be collapsed or expanded, but if the force be applied thereto, in say a vertical plane, the pins will serve to lock the bracket a ainst the action of such force, forming a balanced parallelogram of forces. Furthermore, with this arrangement, the bracket may be adjusted to any desired position. and will be at all times stable, maintaining equilibrium.

The supporting plate 0 may carry a suitable swinging hinge f adapted to be secured to a wall or desk as desired, and the supporting plate (I may support a carrier member or head of any desired ty e. As shown, said plate carries a small to ephone set g, comprising a standard or frame 9 supporting the transmitter g and receiver g, together with the switching mechanism thereof. It will be obvious that the weight of'the telephone set upon the replacement of'the telephone receiver of the set upon its hook, which would tend to apply a downward force to the bracket, will have no effect upon the adjustment thereof.

WVhile I have shown but a single pair of toggle levers, it will be obvious that the number of pairs may be increased as desired.

I claim:

1. The combination with a pair of opposed tog 'le levers, pivots connecting the ends of sai levers, supports for said levers provided with slots in which said pivots are slidably mounted, said supports being further provided with slots angularly disposed with reference to said first named slots, and pins carried by said levers adapted to ride in the angularly disposed slots to give said levers tram movements.

2. A supporting bracket comprising a pair of opposed toggle levers, supports in which the ends of said levers are movably mounted, said supports being each provided with a slot extending at an angle with respect to the di rection of movement of said ends of the levers and pins carried by said levers arranged to ride in said slots in the supports to give the levers tram movements.

3. An adjustable su porting bracket comprising opposed toggle evers pivotally united at their ends, supports in which the pivots of said levers are movably mounted, each of said supports having slots therein at an angle to the direction of movement of said pivots, and guides carried by said toggle levers adapted to ride in said slots to maintain the bracket stable in any adjusted position.

4. An adjustable su porting bracket comprising opposed toggle evers pivotallyunited at their ends, supports for said levers having main slots in which said pivots reciprocate, said supports having slots therein at right angles to said main slots, and pins carried by said levers adapted to travel in said angular slots, whereby compound tram movements may be imparted to said levers, and force applied to said bracket other than in the direction of contraction or expansion is incapable of varying the adjustment thereof.

5. In an extensible bracket, the combination with a head, of a series of opposed toggle levers by which said head is carried, supports for said levers having angular slots therein, and pins, carried by said levers, arranged to ride in said angular slots to give said levers tram movements and render said levers rigid in the adjusted positions of said head.

6. A supporting bracket for a telephone set comprising a pair of opposed toggle levers pivotally connected together at their ends, supporting plates with respect to which said pivotally connected ends are movably mounted, said supports being each provided with a slot extending at an angle with respect to the direction of movement of said ends of the levers, pins carried by the levers adapted to ride in said slots in the plates to give said lever tram movements, and means carried by one of said plates for supporting a telephone standard.

In witness whereof, I hereunto subscribe my name this 1. 5th day of December A. 1)., 1904.

EDRVARD B. CRAFT. Witnesses:

W. S. DUNCAN, E. F. BEAUBIEN. 

